Cholera in conflict: outbreak analysis and response lessons from Gadaref state, Sudan (2023-2024)

Cholera is an acute, severe, illness caused by infection with Vibrio cholerae. Cholera outbreaks are closely linked to armed conflicts and humanitarian emergencies. This study describes the cholera outbreak amidst conflict in Gadaref state, discusses the possible factors mediated its spread and proposes future improvements in preparedness and response measures.

A retrospective analytical study was conducted using national surveillance records of cholera cases, supported by interviews with key informants involved in preparedness and response, along with a review of state reports, to identify possible factors contributing to the spread and to evaluate the response.

The outbreak was confirmed after the isolation of Vibrio cholerae of O1 serotype, with both Inaba and Ogawa serogroups. A total of 2,047 cholera cases records reviewed. The mean age was 16.8 (SD, 15.8) with an equal gender distribution. The case fatality ratio was 2.4% and the overall attack (AR) rate was 7.38 cases per 10,000 population, with the highest in Medeinat Gadaref locality (21.07/10,000). Interviews and reports review suggest that the outbreak was likely imported to villages near Ethiopian border before spreading to other parts of Gadaref. Atbara seasonal river, was the identified source of infection at the beginning. A disrupted health system due to conflict, delays in response teams' deployment, and late implementation of control measures were identified as factors contributing to response delay and expansion of the outbreak. Oral cholera vaccine campaign was implemented in five localities, followed by an observable decline in cases.

Cholera remains a recurrent risk that has been further exacerbated by the armed conflict. The reporting of index cases from a border village highlights the need to strengthen surveillance at points of entry. Investment in case management and risk communication is necessary to improve clinical outcomes. The use of Oral Cholera Vaccine was associated with a decline in cases; however, further field studies are recommended to analyze its actual contribution in limiting the outbreak. The government's primary role in leading and financing preparedness and response interventions has been limited by the conflict, urging investment in community-led interventions, while moving to more strategic outbreak preparedness and response financing mechanisms remains a priority, with partner support being essential in conflict settings.